1. Field of the Invention
This invention is directed toward an improved cutting tooth holder for a circular saw.
The invention is also directed toward an improved circular saw incorporating the improved cutting tooth holders.
The invention is further directed toward a feller head incorporating the improved circular saw.
2. Description of the Prior Art
Circular saws, having cutting teeth mounted on the periphery of a circular saw disk, are now commonly used on feller heads for felling trees. The saw is mounted at the bottom of the felling head and is rotated in a generally horizontal plane. The felling head is moved horizontally to have the rotating saw cut through a standing tree. The felling head often carries a fixed, generally horizontal butt plate that lies closely adjacent to the upper surface of the saw. The cutting teeth of the circular saw cut a wide enough kerf in the tree being felled that allows both the saw disk and butt plate to freely enter the kerf. When the tree is cut through, it drops onto the butt plate. Arms on the felling head can hold the cut tree upright on the butt plate while another tree is cut or while the felling head is moved to transport the cut tree to another station for further processing.
The cutting teeth of the circular saw can be mounted on the saw disk in various ways. One preferred way of mounting the cutting teeth is to use clevis-shaped tooth holders as shown in U.S. Pat. No. 5,058,477, issued to Charles MacLennan on Oct. 22, 1991. Each holder usually holds one tooth and comprises a body portion having a pair of dependent legs. The holder is mounted over the edge of the circular disk with the legs straddling the disk. A peripheral edge portion of the disk snugly enters the slot between the legs of the holder. Bolts passing through the legs and disk securely connect the holder to the disk. The cutting tooth is mounted adjacent one end of the body portion just outside the peripheral edge of the disk with its cutting edges facing in the direction of rotation of the saw.
The holders described above work quite satisfactorily. However, because the legs of the holders extend radially inwardly some distance over the saw disk, they limit the size of the butt plate that can be used. The outer edge of the butt plate, to clear the inner ends of the legs of the tooth holders, must be spaced inwardly some distance from the rim of the saw disk. Thus, a fairly wide peripheral portion of the saw disk is left uncovered by the butt plate. This uncovered portion of the rotating disk may catch the butt of the tree just as it is cut through and drops and flip it off the felling head.